Purification process of high-purity ammonia

Abstract

The invention relates to a purification process of high-purity ammonia, and the purification process comprises: passing raw material ammonia in a storage tank through an oil filter and a water filter to remove water and oil impurity particles therein, then introducing the raw material ammonia into a rectifying tower for rectifying treatment, collecting the separated high-purity ammonia in a high-purity tank at the bottom of the rectifying tower, removing water from the high-purity ammonia with the water filter and condensing with a condenser to obtain qualified liquid high-purity ammonia. Compared with the prior art, by using a process technology route successively comprising low-temperature parallel multi-stage circulated adsorption, multiple ladder-type filtration, low-temperature distillation, online detection and liquid package, provided by the invention, the purity of NH3 can achieve 7N (99.99999%), the purification process has low cost and high stability, the gas space velocity is optimized, the adsorption efficiency is improved, and CO, CH4, N2, heavy hydrocarbons containing 6 or more carbon atoms, organic amines, sulfides and other impurities more difficult to remove are successfully removed.

Description

technical field [0001] The invention relates to a process for purifying ammonia, in particular to a process for purifying high-purity ammonia. Background technique [0002] High-purity ammonia is the main raw material for microelectronic silicon nitride masking film, and its reaction is: SiH at 850°C 4 +NH 3 -> Si 3 N 4 +H 2 N 2 , 900°C SiCl 4 +NH 3 -> Si 3 N 4 +HCl N 2 . Although NH 3 The amount used in semiconductor manufacturing is not large, but in the field of optoelectronics, high-purity ammonia is a very important raw material. NH 3 The quality of the LED directly determines the brightness of the light-emitting diode (LED), and its price determines the economy of the LED. Light-emitting diodes (LEDs) are another revolution in the lighting industry for mankind after Edison invented the electric light. Developed countries (including Taiwan Province of my country) have established national lighting committees in succession in order to gain greater ini...

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Problems solved by technology

In addition, the raw materials for ammonia production in my country, such as coal, oil, and natural gas, are not as good as the above-mentioned developed countries, resulting in uneven quality of industrial ammonia used as raw materials for purification, which brings great inconvenience to the purification.

Especially the NH synthesized from natural gas 3 , where CO, CH 4 The content is relatively high, and it is found that it contains a lot of C 6 The above heavy carbon hydrocarbons, organic amines, sulfides and other impurities are difficult to remove by the above-mentioned conventional methods of foreign gas plants

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